Jetty installation



July 22, 1958 e. w. REHFELD 2,844,005

JETTY INSTALLATION Filed March 24, 1955 2 Sheets-Sheet 1 IN V EN TOR.

6e0rge 14 Rehfe/d W M 14 TTORNEYS.

July 22, 1958 G. w.- REHFELD 2,844,005

JETTY INSTALLATION Filed March 24, 1955 h 2 Sheets-Sheet 2 IN V EN TOR;

(Geo/9e n4 Rehfe/d.

MAW

A TTORNEVS.

United States Patent This invention relates to jetties for building upand protecting the banks of streams from erosion. For instance, it isthe practice to install lines of jetties along the bank of a stream,where erosion occurs 'or where new banks are to be established. Thejetties, whichare contained in the stream and those within flood waters,retard the flow sufficiently for the debris, which is-carried by thecurrent, to settle and deposit around the individual jetties, but thejetties to be efiective must rest upon the ground or bank of the stream,which they protect. When the jetties do not maintain ground contact,erosion starts thereunder and any silt that settles from the water iscarried away by the underflow and soon large cavities are formed underthe jetties. This condition occurs most readily where the bank mergesinto the bottom of the stream because the jetties are prevented fromsettling due to their support by the main anchoring lines. When theunderwash becomes extended, the load of the jetties on the main lines,in addition to the added strain produced by the current and pressure ofthe driftwood thereon, may cause the lines to part and the jetties arelost .or shifted out of position by the current. I

The principal object of the present invention is to provide anarrangement of jetties and anchorage therefor, which leaves the jetties,which are most subject to underflow, free to settle and maintain contactwith the ground. If there should be any tendency to underwash, thejetties settle therewith and retard the flow so that silt and debrissettling from above can fill around the legs of the jetties to therebyreverse the procedure and build up the bank of the stream.

In accomplishing these and other objects of the invention, hereinafterpointed out, I have provided improved structure, the preferred form ofwhich is illustrated in the accompanying drawings wherein:

Fig. 1 is a cross-section through the bank of a stream,

illustrating a jetty installation, embodying the features of the presentinvention.

Fig. 2 is a plan view.

Fig. 3 is a cross-section similar to Fig. 1, but showing a portion ofthe jetties shifted into position for stopping erosion and filling inthereof to build up the bank of the stream.

Fig. 4 is a perspective view of one of the preferred type of jettyunits.

Fig. 5 is an enlarged fragmentary perspective view of the jettyillustrated in Fig. 4, showing the connection of the members composingthe jetties.

Referring more in detail to the drawings:

1 designates the bank of a stream 2, wherein the current indicated bythe arrows 3 tends to erode the bank 1 to ultimately change the courseof the stream. Such erosion often occurs upstream from the site of abridge or other place where it is most important to maintain theoriginal course of the stream, through protection of the bank in amanner to stop erosion and 2 build up the bank for diverting the streaminto its regular course. This is accomplished, in accordance with thepresent invention, by a system of jetties 4. The jetties 4 reduce thevelocity of the current, causing debris carried thereby to settle andbuild up the bank for diverting the current in the desired direction.

In carrying out the present invention, lines of jetties 5, 7, 8, 9 and10 are arranged somewhat transversely of the bank 1 of the stream 2 andspaced apart to cover the area subject to erosion. Each line of jettiesis composed of a plurality of individualjetties 11 that are connectedtogether by lines 12 such as acable or'ser'ieso'f intercoupled rods.

While the invention can be carried out with jetties of various types,best results are obtainedby jetties of the type illustrated in PatentNumber 2,669,844, issued to me February 23, 1954. Jetties of this typeinclude angle iron members 13, 14, and 15 arranged in the form of atripod, with flanges 16 of the respective members in crossing relationand secured together by fastening devices such as bolts 17 as shown in(Fig. 5. The members 13, 14 and '15 when thus connected provideoutwardly diverging legs 18 and upwardly diverging arms19 as shown inFig. 5. The bolts .17 extendthrough suitable openings 29 that areprovided in the flanges 116. T he flanges 16 of the respective jettymembers are also provided with apertures 21 spaced apartalong the lengththereof for passing a lacing 22 that increases the effectiveness of thejetties in obstructing andretardingjflow of water and forcollecting thedebris and silt that settles around the legs 18 of the jetties.

When the lines 12 aremade .up of rods, the ends of the rods 23amconnected bysuitableclamps and the Qjetties are .connected therewith at,the.,crossing points of the members 13, 14 and 15. The connectionsbeing ,made by passing the line 12along-one side of a jetty and securingit thereto by a section of ,rod .24 at .theopposite side withthe ends ofthe ,section25 clamped to. or twisted around the line 12 as shown at 26and '27 in Fig. 4.

A sufficient number of jetties are applied to each line 12 to extendfrom the bottom of the stream upwardly and over the bank 1 to a distancepreferably for covering the extent of overflow during flood periods asshown in Fig. 1. The land end 28 of each of the lines 12 is connected toa deadman 29 or other suitable anchorage preferably located in aconvenient position for forming a solid anchorage where it is notsubject to erosion during times of high water. The line 12 for the firstjetties 5 up stream has an extension 30 that crosses all the other linesat points substantially in alignment with the bank and the extension issecured to the nearest jetty in the respective lines in the manner ofthe lines 12 as shown in Fig. 4, to leave the stream ends 31 of thelines of jetties 7, 8, 9 and 10 substantially free to move.

In this way, the cable for the line of jetties 5 and its extensions actsas a main line cooperating with the deadmen 29 in maintaining a spacedrelation of the transverse lines of jetties 5, 7, 8, 9 and 10 and toprevent swinging thereof about the deadrnenZ? during times of highwater. The movable ends or sections 31 of the jetties are free to swingabout the connections with the extension or main line and to movedownwardly so as to adjust themselves to the slope of the band andbottom of the stream and to permit settling thereof in case the streamshould tend to underwash the jetties as shown in Fig. 3. Since thesection of jetties 31 are free to move, they settle with any erosionthat might take place so as to stop the erosion and retain the silt andother debris that settles because of retardation of the water.

When installing the jetties in accordance with the present invention,the deadmen 29 are suitably located and the lines 11 are connectedtherewith, after which'the jetties are'erected, laced and attached alongthe lines 12 as above described and shown in Fig. 4. The lines ofjetties are then moved into position with the end sections 31 thereofextending down the bank and into the Water to rest upon the bottomof thestream at the points where erosion is most apt to occur. The extension30 is extended across the transverse lines 12 for connection with one ofthe jetties in each of the respective lines 7, 8, 9 and 10 as shown inFig. 2 so as to substantially and firmly anchor jetties that extendlandward of the bank and to leave one ormore freely movable jettieswithin the Water of the stream or Within the water when high Wateroccurs. These jetties, being movable, are self-adjusting to the bottomof the stream and prevent erosion, or if erosion should occur, thejetties effect filling in by the silt and other debris carried in thestream.

As above stated, one of more freely movable jetties may be used on eachline 12 depending upon the depth and contour of the bank, the numberbeing sufficient to protect the bank at the places where erosion is mostlikely to start. It is obvious that any number of lines of jetties maybe used and that the freely movable sections may be provided on one ormore of the lines 12 as the particular installations demand.

From the foregoing, it is obvious that I have provided an improved jettyinstallation, which reduces erosion and builds up the bank on which thejetties are installed.

What I claim and desire to secure by Letters Patent is:

1. A jetty installation for protecting the bank of a stream from erosionincluding a plurality of spaced apart parallel lines of jettiesextending transversely relatively to'the bank of the stream and havingends remote from the stream and opposite ends in position to beunderwashed by water of the stream, anchors connected with said remoteends of the lines of jetties, a tie line extending across the lines ofjetties intermediate said ends to provide a substantially fixed sectionof jetties and a movable end section of jetties in each of said lines ofjetties, said movable end sections being adapted to maintain groundcontact separately of the fixed sections.

2. A jetty installation for building up and protecting the bank of astream from erosion, including an anchor line extending transverselyrelative to the bank of the stream, nonfloating jetties connected withthe anchoring line and all adapted for support upon the ground, saidanchoring line having an end remote from the stream and an opposite endextending down the bank of the stream, means for anchoring said remoteend of the anchoring line, a tie line extending transversely of theanchoring line intermediate said ends to provide a substantially fixedsection of jetties for effecting building up of the bank of the streamduring times of high water, and a freely movable section of jetties formaintaining ground contact with the bed of the stream and subjected tocurrents tending to underwash the bank of the stream, said movablesection of jetties being adapted to settle and maintain ground contactindependently of the fixed section of jetties to stop any underwashingaction of the current of said stream.

3. A jetty installation for building up the ground alongside a streamwherein the current of the stream'tends to underwash the ground to bebuilt up, said jetty installation including spaced apart substantiallyparallel anchoring lines, nonfloating jetties spaced along the lines andarranged to rest upon said ground, means connecting the jetties to thelines for maintaining spaced apart relation of the jetties, an anchorsecuring one end of each parallel line remotely of the stream, a tieline interconnecting the parallel anchoring lines substantiallyalongside said stream to cooperate with the anchors in maintaining fixedrelationship of the jetties upon the ground to be built up, said jettieson the stream side of said tie line at free ends of the anchoring linesbeing freely movable on the ground at the points subject to underwashand adapted to settle independently of the relatively fixed jetties tostop any underwashing action of the stream.

References Cited in the file of this patent UNITED STATES PATENTS780,437 Neale Jan. 17, 1905 1,662,578 Kellner Mar. 13, 1928 2,082,707Mahon June 1, 1937 2,106,564 Fiske et a1. Jan. 25, 1938

